Biologists have demonstrated the diversity of developmental patterns in modern vertebrate appendages (e.g. zebrafish, mouse), assuming that they are representative of the group they belong to (respectively, ray-finned fishes and tetrapods). However, it is likely that long-bone microstructures in these models are highly derived and may not reflect their original function. The recent development of high-resolution synchrotron virtual histology has permitted to access the three-dimensional bone microstructure of basal ray- and lobe-finned fishes. Based on illustrated study cases, I will focus on two major points: 1) the origin and development of one of the two processes by which bone is formed in the appendicular skeleton: endochondral ossification; 2) the evolution of bone marrow functions in long bones.

The lecture is an examination to be admitted as a docent and should be at the knowledge level of undergraduate students but could also be of interest to a wider audience. The lecture is 45 minutes and is followed by time for questions and discussion. The lecture will be given in English.